The present invention relates, in general, to articles such as semiconductor devices and, more particularly, to encapsulating the articles.
Semiconductor devices are typically manufactured from a semiconductor wafer. The wafer is then diced up to form chips or dice, which are mounted to a substrate such as a leadframe or a printed circuit board. The leadframe or printed circuit board is then placed in a mold and encapsulated in a molding compound.
The molding compound is typically injected into the mold under a high pressure and an elevated temperature. Because of the high pressures exerted in liquefying and extruding the molding compound, vents are included in the mold to provide a pressure release mechanism. However, the vents tend to accumulate molding compound during each encapsulation step necessitating cleaning of the molds after each use. Further, the vents become worn over time and are subject to damage. Once worn or damaged, the molds need to be replaced. As those skilled in the art are aware, molds are very expensive.
Accordingly, it would be advantageous to have a method and apparatus for encapsulating semiconductor devices that is useful for a large number of device types and that extend the useful life of a mold. It would be of further advantage for the method and apparatus to be cost efficient and easily integrable into existing manufacturing processes.